The biochemistry and physiology of circulating pancreatic proelastase is being investigated. The molecular forms of proelastase (free or bound to plasma inhibitors) are being determined for normal human plasma, and will be investigated for several disease states. The physiological mechanisms controlling the levels of circulating pancreatic proelastase will be identified in a dog model. The potential activators of circulating pancreatic proelastase will be identified and characterized.